Moving fuel bundles between locations in a nuclear facility containment building is often subject to a minimum critical path time schedule, which determines the length of time a nuclear power plant is unavailable for consumer energy production.
By way of background, nuclear reactors subject to such a movement of fuel bundles are discussed in "Nuclear Power Engineering" a work by M. M. El-Wakil, which was published by McGraw-Hill in 1962. The fuel bundles themselves are described in useful detail in U.S. Pat. No. 3,431,170, which is incorporated herein.
The nuclear reactor is but one element of a larger facility which will be described hereinafter. It should also be noted at this point that the movement of fuel referred to above may involve refueling the nuclear reactor or the initial fuel loading of the reactor or it may even involve the movement of fuel within the reactor facility which is not related directly to loading or unloading fuel in the reactor itself at all. Furthermore, it is notable that there is a movement of reactor facility equipment in "picking up" a fuel bundle which is very closely related to the movement of equipment involved in moving the fuel bundle after it has been "picked up." These ancillary equipment movements are considered to be included in the penumbra of activities falling under the phrase "moving the fuel bundles."
At present, nuclear fuel in the form of fuel bundles is moved by an operator manually operating controls in an operators cab in the trolley of a fuel transfer platform within the containment building or structure of a nuclear reactor facility. The fuel transfer platform includes a bridge spanning two rails in the floor of the containment building, the trolley just mentioned, and a hoist/grapple arrangement to be further discussed. This arrangement actually lifts and holds the fuel bundle preliminary to and during movement from one part of the facility to another.
The speed and predictability of the movement of fuel understandably varies with the skills and the discipline of the operator. For some portions of the transfer of fuel procedure his skill and judgement are indispensable. For other more routine and repetitive tasks, he would gladly delegate functional responsibility to a more automatic system. The instant invention to be described herein involves such a system.
In accordance therewith, an object of the instant invention is to reduce the minimum critical path time of refueling in nuclear facilities.
Furthermore, an object of the instant invention is to reduce the time of movement of a nuclear fuel bundle being transferred between locations in the containment structure of a nuclear facility.
Another object of the instant invention is to reduce overall facility outage times related to moving nuclear fuel between locations in a reactor core and fuel storage pool.
An additional object of the instant invention is to reduce and make more predictable the pick-up and transfer times of nuclear fuel bundles within the containment of a nuclear reactor facility.
Yet another object of the instant invention is to effect all movements in a critically damped fashion when repositioning a loaded or unloaded refueling platform toward a selected hoist/grapple destination.
Even another object of the instant invention is to automate a portion of the fuel handling procedure in nuclear facilities.
A final listed object of the instant invention is to reduce the consumer cost of nuclear facility plant outages.